Truing apparatus



sept. 29, 1936. ||n J GRlFFiNG 2,056,149"

TRUING APPARATUS Filed Oct. 28, 1955 d 3/ Z9 44 i l l L 30 27 /6 iHERBERT J. ER/FF/NG y @1Mo-mui@ Gummi Patented Sept. 29, 1936 UNITEDSTATES PATENT OFFICE TBUING APPARATUS tion of Massachusetts ApplicationOctober 28, 1935, Serial No. 47,031

7 Claims.

This invention relates lto grinding machines, and more particularly to agrinding wheel truing apparatus for generating a predetermined form onthe operative face of a grinding wheel.

One of the objects of this invention is to provide a simple andthoroughly practicable formed wheel truing apparatus. Another object isto provide an improved grinding wheel forming apparatus which permitsproducing irregular curved surfaces and shapes upon the operative faceof a grinding wheel while maintaining the truing vtool or diamond in asubstantially predetermined angular relation with the surface beingtrued.

A. further object of this invention is to provide a radial truing devicewhich is adapted to produce an irregular form on the operative face of agrinding wheel. Other objects will be in part obvious and in partpointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts as will beexemplified in the structure to be hereinafter described, and the scopeof the application of which will be indicated in the following claims.

In the accompanying drawing, in which is shown one of the variouspossible embodiments of the mechanical features of this invention,

Fig. 1 is a fragmentary cross-sectional view of a grinding machine,showing the wheel truing apparatus in section;

Fig. 2 is a plan view of the radial truing device, with the operatinghandle removed; and

Fig. 3 is a horizontal sectional view, taken approximately on the line3-3 of Fig. 1.

A grindingmachine has been illustrated comprising a base I0 and atransversely movable wheel slide II mounted on ways (not shown) on thebase. The wheel slide II supports a rotatable wheel spindle I2 which inturn supports a rotatable grinding wheel I3.

The grinding wheel slide II may be moved transversely by any cfthewell-known feeding mechanisms, such as that shown in the prior U. S.patent to Norton No. '162,838 dated June 14,` 1904, to which referencemay be had for a detailed disclosure of the feeding mechanism. Such a4feeding mechanism may comprise a half nut I4 depending from the wheelslide II which engages or meshes with a rotatable feed screw I5journaled in suitable bearings (not shown). The front end of the feedscrew I5 is provided with a gear I6 meshing with a gear I1 on the innerend of a shaft I8. The shaft I8 is rotatably supported in bearings (notshown) in the base III and is provided with a gear I9 on its front endwhich may be turned by a manually operable feed mechanism, such as thatshown in the prior patent to Norton above referred to.

A longitudinally movable work table 25 is slid- 5 ably mounted on theflat way 26 and a V-way 21 and arranged so that it may be movedvlongitudinally relative to the base I 0. The table 25 supportsa swiveltable 28 which, as shown in the above-mentioned prior patent, serves asa l0 support for a headstock and footstock (not shown) or a truingapparatus, as illustrated in the drawing.

The table 25 may be moved longitudinally either manually or by means ofa power operated l5 traversing mechanism. For the sake of simplicity ofillustration, however, a manually operable hand traverse mechanism hasbeen illustrated. The table 25 is provided with a depending rack barI 29which meshes with a gear 30 mounted on 20 the inner end of a rotatableshaft 3| which is `iournaled in the base III. The outer end of the shaft3l is provided with a manually operable traverse wheel 32 so that thetable may be traversed longitudinally relative to the base I 0 by 25rotating the hand Wheel 32.

The improved truing apparatus has been illustrated as mounted on theswivel table 28 of a grinding machine, as above described. The truingapparatus comprises a base member 35 which 30 is provided with bearingsurfaces 36 and 31 arranged tomate with corresponding surfaces on theswivel table 28. The truing apparatus base 35 is arranged so that it maybe clamped rigidly to the swivel table 28 by means of a clamping 35member 38 which is pivotally mounted on a stud y 39 and arranged toengage a dovetailed surface 40 on the upper surface of the swivel table28. The clamping member 38 is actuated by means of a clamping screw 4Iso that the truing apparatus 40 base 35 may be rigidly clamped inposition on the swivel table 28. p

'I'he truing apparatus comprises a pivotally mounted frame 42 which ispreferably arranged to swing about a fixed axis in a circular path. 45

The lower end of the frame 42 is provided with a trunnion 43 supportedin a bearing 44 in the frame 35. The upper portion of the--steadyrestbase 35 is provided with a circular track 45. The track 45 is preferablyformed-as an integral part 50 of a plate 48which is fixed to thesteadyres.. base 35 by means of the screws 41 and 48. The upper end ofthe frame 42 is provided with a follower plate 49 having a groovedfollower surface 50 which is shaped to mate with the track 45. 55

The follower 43 and track 45 serve as a rigid support for the upper endof the truing apparatus 4frame 42 so that it may rigidly support atruing' .tool during its swinging movement in a circular path about theaxis of the trunnion 43 as a pivot.

In the preferred construction, the frame 42 is provided with a suitablemeans for holding the frame in a iixed position so that the truingapparatusmay be utilized for truing a true cylindrical surface on thewheel being trued, if desired. The follower plate or bracket 49 isprovided with a notch 52 which may' be engaged by a slidably mountedplunger 53 carried by the track plate- 46 so that the frame 42 may beheld in a iixed ually operable handle 55 is mounted on the upper end ofthe frame 42 so that the frame 42 may be readily swung in a circularApath for truing the grinding wheel.- y

In order that a grinding wheel may be accurately trued to the desiredpredetermined form, it is essential that the diamond or truing tool bemoved across the face of the wheel while the diamond or truing toolbears the same angular relation with-the wheel at the point ofcutrelative to the swinging frame as the frame isv swung through acircular path to true a predetermined contour on the periphery of thewheel being trued. As illustrated in the drawing, a diamond or truingtool is mounted in the front end of a transversely movable sleeve 6|which is slidably mounted within a cylindrical bore S2 in an enlargedportion 63 of the frame 42.` The other end of the sleeve 6I is providedwith a follower 64 which is arranged to engage and follow the surface ofa template or form 65 as the frame 42 is swung in a circular path. Aspring 66 is contained within an enlarged bore 61 in the portion B3 ofthe frame 42 and is interposed between the bottom surface 68 of the bore61 and a flange 69 mounted on the end of the truing tool sleeve orholder 6|. The compression of the spring 66 serves to maintain thefollower 84 in operative engagement with the cam or form 65 as the frame42 is swung in a circular path, therel by causing the holder 6I and thetruing tool 60 to move transversely toward and from ,the wheel axis soas to generate a predetermined shape or contour on the peripheralsurface of the wheel.

By providing a template or cam 65 which is provided with a properlyshaped surface to generate a predetermined contour on the wheelperiphery, any desired shape may be produced. By utilizing a swingingmotion of the truing tool while the truing tool is mo'ved transverselyrelative to said motion, the truing tool is moved disclosure. A form ortemplate 65 is provided having a properly shaped cam surface to cause apredetermined transverse movement of the truing tool as it is swungthrough a circular path. The form or template B5 is mounted in place onthe truing tool base, the feeding mechanism is then actuated to move thegrinding wheel I3 transversely into operative contact with the diamondor truing tool 60. The plunger 53 is then withdrawn from the notch 52andthetruing tool frame 42 is swung through a circular path by means ofthe handle 55 while the truing tool is moved transversely by form 65 togenerate a predetemiined form` on the face of the grinding position onthe truing apparatus base 35. A mane.

wheel. By manipulating the feeding mechanism.' the grinding wheel may beadvanced to true the surface thereof to the desired extent.

If it is desired -to true a cylindrical surface on the wheel I3, theplunger 53 is moved into engagement with the notch 52 to lock the frame42 against a swinging movement. The table 25 may then be traversedlongitudinallyby means of the manually operable traverse wheel 32 topass the truing tool 60 across the operative face of the grinding'wheelI3.

It will thus be seen that there has been provided by this inventionapparatus in which the various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of `the above invention and asmany changes might be made in the embodiment set forth, it is to beunderstood that all matter hereinbefore set forth or shown in theaccompanying drawing is to be interpreted as illustrative and not in alimiting sense;

1. A truing apparatus for a grinding machine comprising a truinglapparatus base, means to clamp said base onv a grinding machine, apivotally mounted frame which is arranged to swing in a circular path, apivotal bearing support for the lower end of said frame, means to guidethe upper end of said frame, a. truing tool, atruing tool holderslidably supported on said frame and movable transversely relativethereto, and means including a cam to slide the holder transverselyrelative to the frame as the frame is swung about its pivot. to causethe truing tool to produce a predetermined shape on the. grinding wheelperiphery.'

2. A truing apparatus for a grinding machine .comprising atruing'apparatus base, means to a sliding surface on said holder, amating slide surface on said frame, a follower associated with saidholder, and means including a cam to move the holder transverselyrelative to the frame as the frame is swung about its pivot to cause thetruing tool to produce a predetermined shape on the grinding wheelperiphery.

3. A truing apparatus for a grinding machine comprising a truingapparatus base, means to clamp said base on a grinding machine, apivotally mounted frame which is arranged'to swing in a circular path, atruing' tool, a transversely movable truing tool holder supported onsaid frame, mating slideways on said holder and frame, a followerassociated with'said holder, and an interchangeable cam vto move theholder transversely in its slideway relative to the frame as the frameis swung about its pivot to cause track and serves to guide and supportsaid frame,

a truing tool, a truing too-l holder supported on said frame andarranged to move transversely relative thereto, and means to move theholder and tool transversely as the frame is moved on said track totraverse the truing tool across the grinding wheel face to generate apredetermined shape thereon.

5. A truing apparatus for a grinding machine comprising a truingapparatus base, means to clamp said base on a grinding machine, apivotally mounted frame which is arranged toswing in a circular path, atrunnion on the lower end of said frame, a bearing for said trunnion onthe base, a circular track on said base, a follower adjacent the upperend of said frame which mates with said track and serves to guide andsupport the upper portion of said frame, a truing tool, a truing toolholder supported on said frame and arranged to move transverselyrelative thereto, and means to move the holder and tool transversely asthe frame is swung about its pivot to traverse the truing tool acrossthe grinding wheel face to generate a predetermined shape thereon.

6. A truing apparatus for a grinding machine comprising a truingapparatus base, means to clamp said base on the grinding machine table,a pivotally mounted frame which is arranged to swing through a circularpathfa bearing support for the lower end of said frame, means toguidesaid frame as it swings in a circular path, a trus ing tool, atruing tool holder which is arranged to move transversely relative tothe frame, mating slideways on said holder and frame, yieldable meanstending to move the truing tool away from the grinding wheel, a followercarried by said holder, and a removable form which is engaged by saidfollower and serves to move the truing tool transversely relative to theframe as the frame is swung about its pivot to produce a predeterminedshape on the periphery of the grinding wheel.

7. A truing apparatus for grinding machines comprising a base, means toclamp said base on a grinding machine, a pivotally mounted frame whichis arranged to swing in a circular path, a trunnion on the lower end of.said frame, a bearing for said trunnion on the base, a circular track onsaid base, a follower engaging the upper end of said frame which mateswith said track and serves to guide and support the upper portion ofsaid frame, a truing tool, a truing tool holder supported on said frameand arranged to move transversely relative thereto, yieldable meanstending to move the truing tool and holder away from the wheel, and aform removably mounted on said frame which is engaged by said followerand serves to move the truing tool and holder transversely as the frameis, swung about its pivot to traverse the truing tool across thegrinding wheel face to generate a predetermined shape thereon.

HERBERT J. GRIFFING.

